Minimize all JavaScript files in a folder (recursive) using Google Closure Compiler Web Service API

#!/usr/bin/python

import httplib, urllib, sys
import os
import fnmatch

def googleClosureCompiler(rpath, wpath):
	f = open(rpath, 'r')
	s = f.readlines()
	s = "".join(s);
	f.close()

	params = urllib.urlencode([
	    ('js_code', s),
	    ('compilation_level', 'SIMPLE_OPTIMIZATIONS'),
	    ('output_format', 'text'),
	    ('output_info', 'compiled_code'),
	  ])
	f.close();

	headers = { "Content-type": "application/x-www-form-urlencoded" }
	conn = httplib.HTTPConnection('closure-compiler.appspot.com')
	conn.request('POST', '/compile', params, headers)
	response = conn.getresponse()
	data = response.read()
	conn.close
	f = open(wpath, 'w')
	f.write(data)
	f.close()

for top, dirs, files in os.walk('YOUR-JAVASCRIPT-FOLDER'):
    for nm in fnmatch.filter(files, '*.js'):
	s = os.path.join(top, nm)
	if s.find('/test/') == -1:  # Ignore /test folder
		googleClosureCompiler(s, s.replace('.js', '.min.js'))

You better use kjscompiler - makes compilation of multiple JavaScript files with Google Closure Compiler application in right order.
https://github.com/knyga/kjscompiler